Wayward pollen and seed from genetically modified crops have cost Canadian honey producers and organic farmers millions of dollars, according to researchers who say there is an urgent need to better control the controversial GM crops and their novel genetic machinery.

"It is essential that new molecular gene-containment strategies be developed and introduced," says a report in the journal Nature Biotechnology this month, which points to the significant economic risks and liabilities associated with GM crops now widely grown in Canada and the United States.

In the most costly case to date, GM corn meant only for animals ended up in U.S. food in 2000. The resulting scramble to recall tacos and corn products cost "a staggering US $1-billion," the report says. Canadian honey producers and organic farmers, the report says, are also paying a big price.

The European Union recently banned imports of Canadian honey because Canadian producers cannot guarantee their honey is free of pollen from GM plants not yet approved by the EU.

"This action by the EU has driven down domestic honey prices in Canada and cost the industry a market that has on average earned more than $5.3-million over the past decade," Peter Phillips, an agricultural economist, and his colleagues at the University of Saskatchewan say in a paper that is part of the journal's special report on GM plants and trees.

These modified crops and their pollen, which can be carried up to 25 kilometres on Prairie winds, also "destroyed the growing, albeit limited, market for organic canola," say Prof. Phillips and his colleagues. "Because of the likelihood of out-crossing and pollen flow, buyers have shown increased reluctance to buy organically produced Western Canada canola because it might contain transgenes."

Transgenes, made from genes borrowed from microbes, animals or other plants, are engineered into GM crops to confer new traits such as resistance to insects, drought or herbicides.

The researchers estimate the lost market to Canada's organic farmers at between $100,000 and $200,000 annually. "But the calculation probably underestimates the opportunity cost of a market that many thought had significant potential for growth," they say.

Saskatchewan's organic farmers recently launched a class-action suit against Monsanto and Aventis, biotech companies that sell herbicide-resistant GM canola widely grown in Canada, arguing the companies should be liable for lost sales due to contamination by its GM genes.

While the courts will eventually rule on that case, Prof. Phillips and his colleagues say industry and government regulators must do a better job of controlling GM crops and the pollen and seed they produce.

Their report focuses mainly on the significant liability cost of genes from GM crops "escaping and going rogues," but scientists writing in the journal also say there are many unanswered questions about the long-term environmental risks of GM plants.

There is concern transgenes will be picked up by weeds and other plants and make them even hardier.

As evidence of problems, the journal editors point to Canada, where "canola plants resistant to three herbicides have emerged in just two years as a result of cross-pollination."

The resistant plants developed when an Alberta farmer, unaware of the risks, planted different varieties of canola too close together.

Allison Snow, an ecologist at Ohio State University, says more research on gene flow from GM crops is sorely needed. She notes that a transgene used in GM crops to promote insect resistance can result in an unexpectedly large boost in seed production in wild sunflowers.

"Current gene-containment strategies cannot work reliably in the field," says an editorial in the journal. "Seed companies will continue to confuse batches, and mills will continue to mix varieties." And farmers will continue to be "unable or unwilling" to follow planting rules aimed at controlling unwanted dispersal, or flow, of genes from GM crops into non-GM crops.

"Most seriously, gene flow could result in GM material unintended for human consumption ending up in the human food chain," says the editorial, which raises the possibility of "biopharmaceutical" GM crops, designed to produce drugs, contaminating food.

"It is time that industry took decisive steps to address gene flow from their products," it says. "Environmental concerns surrounding GM crops are not going to go away."

Prof. Phillips and his colleagues say they would like to see a reassessment of gene containment techniques such as Monsanto's "terminator" technology, which can produce sterilized seed and prevents genes from being passed on.

It stirred up a huge controversy a few years ago. Critics in the developing world expressed concern the seed-sterilizing technology would reduce biological diversity and increase corporate concentration in agriculture.

Prof. Phillips and his colleagues say terminator-type technologies could be useful in solving some GM crop problems. The technologies could act as a "built-in safety mechanism to prevent the escape or spread of potentially harmful traits (such as herbicide tolerance) from new GM crops."

And the technology could reduce the liabilities of GM crop producers "by preventing contamination through co-mingling with non-GM crops."